When to plant Onions in Iowa
In spring, from Mar 1 – Apr 1 in Burlington to Apr 1 – May 1 in Waverly.
In fall: USDA's 1967 table lists onion plants as generally spring-planted in every place here. Newer advice from your state's extension service may differ.
Dates are for setting out plants. USDA's earliest safe spring and latest safe fall planting dates, matched to each place's average frost dates.
| Place | Spring |
|---|---|
| Altoona | Mar 15 – Apr 10 |
| Ames | Apr 1 – May 1 |
| Ankeny | Mar 15 – Apr 10 |
| Bettendorf | Mar 15 – Apr 10 |
| Boone | Apr 1 – May 1 |
| Burlington | Mar 1 – Apr 1 |
| Carroll | Apr 1 – May 1 |
| Cedar Falls | Apr 1 – May 1 |
| Cedar Rapids | Apr 1 – May 1 |
| Clinton | Mar 15 – Apr 10 |
| Clive | Mar 15 – Apr 10 |
| Coralville | Mar 15 – Apr 10 |
| Council Bluffs | Mar 15 – Apr 10 |
| Davenport | Mar 15 – Apr 10 |
| Des Moines | Mar 15 – Apr 10 |
| Dubuque | Mar 15 – Apr 10 |
| Fort Dodge | Apr 1 – May 1 |
| Grimes | Mar 15 – Apr 10 |
| Indianola | Mar 15 – Apr 10 |
| Iowa City | Mar 15 – Apr 10 |
| Johnston | Mar 15 – Apr 10 |
| Le Mars | Apr 1 – May 1 |
| Marion | Apr 1 – May 1 |
| Marshalltown | Apr 1 – May 1 |
| Mason City | Apr 1 – May 1 |
| Muscatine | Mar 15 – Apr 10 |
| Newton | Mar 15 – Apr 10 |
| North Liberty | Mar 15 – Apr 10 |
| Norwalk | Mar 15 – Apr 10 |
| Oskaloosa | Mar 15 – Apr 10 |
| Ottumwa | Mar 15 – Apr 10 |
| Pella | Mar 15 – Apr 10 |
| Pleasant Hill | Mar 15 – Apr 10 |
| Sioux City | Apr 1 – May 1 |
| Spencer | Apr 1 – May 1 |
| Storm Lake | Mar 15 – Apr 10 |
| Urbandale | Mar 15 – Apr 10 |
| Waterloo | Apr 1 – May 1 |
| Waukee | Mar 15 – Apr 10 |
| Waverly | Apr 1 – May 1 |
| West Des Moines | Mar 15 – Apr 10 |
Planting dates: USDA Home and Garden Bulletin No. 9 (1967), tables 4 and 5. Frost dates: NOAA U.S. Climate Normals 1991–2020. The full USDA table for onion plants.